Mine-shot-firing system.



G. I. RAWSON.

MINE SHOT FIRING SYSTEM.

APPLICATION FILED MAY 4, 1909.

Patented N0v.;11, 1913.

3 SHEETS-SHEET 1.

. n a 3 w m m NR \u 9Q F 3 FM \& m w M W M Fa Q 8%. w 0 M MW *m N; w

G. I. RAWSON. MINE SHOT FIRING SYSTEM.

APPLICATION IILED MAY 4, 1909.

' Patented Nov. 11, 1913.

3 SHEETS-SHEET 2.

gviuantoz Eran/Z].- ZZd wqan G. I. RAWsoN. MINE SHOT FIRING SYSTEM. APYLIOATION TILED MAY 4, 1909.

11, 191 3. a sums-3113M.

Patented Nov.

Witumuo Q ing Systems, of which the following is a GRANT I. DAWSON, OF ST. LOUIS, MISSOURI.

MINE-SHOT-FIBING SYSTEM;

Specification of Letters Patent.

Application filed May 4, 1909. Serial No. 498,792.

To all whom it may concern:

Beitknown that I, GRANTI. RAWSON, a citizen of the United States, residing at St. Louis, State of Missouri, have invented new and useful Improvements in Mine-Shot-Firspecification. I

The invention is directed to a mine shot firing system, being particularly directed to an apparatus which may be located in the mine adjacent 'the' chambers in which the shots are to be fired and absolutely and accurately controlled from the surface of the mine.

The main object of thepresent invention is theprovision of a machine of this char-.

enter in which the shots are successively fired entirely at the will of the operator,

the latter having such complete control of the machine as will permit starting or stop'- ping of the machine at any point inter-j when the lever 12 is in one position the cam nose thereof will bear upon the upper mediate its initial or final stage.

'A. further object of the invention is the; provision of means whereby the action of said block and the block 17 toward, each the machine will be effectively. recorded at the surface of the mine, the construction insuring the. recording of the operation of' the machine as well as the fact as to the firing of the particular shot.

The invention will be described in the following specification, reference .being had particularly to the accompanying drawings, 111 which Figure l is a diagrammatic view illustrating the electrical connections with the.

machines and the recording apparatus. Fig. 2 is a plan of one of the machines. Fig. 3

' J is a broken transverse section of the same.

Fig. 4: is a longitudinal section.

Referring particularly to Figs. 2 to 4 inclusive, wherein is shown thepreferred type of the machine, 1 represents a casing, preferably of rectangular or other appropriate form, said casing being wholly inclosed except for a slot2 extending longitudinally and centrally of the cover or ,upper wall thereof. In the end walls of the casing and extending centrally thereof is mounted a feed shaft 3, which is threaded in that portion arranged between the end walls. The shaft extends beyond what will be termed the rear end wall .of-the casing to provide a stub shaft 4 on which is mounted a'worm gear 5.

Mounted on the feed shaft 3 is a carriage 6, including a standard 7 formed 1 the greater portion of its length to provide spaced bars 8. Secured on the lower ends of the bars. 8 is a block 9, formed'in its rclatlvely lower surface with a depression 10 nteriorly threaded for cooperation with the feed shaft. The block 9 is formed on it upper surface with vertically arranged spaced ears 11, between which is pivoted an operating lever 12 having a cam nose 13. To the free end of the cam nose of the lever i secured a transversely arranged rod 14, which extends beyond the bars 8- of the standard and is connected at each end to an upright 15 projecting from an inverted U- shaped frame 16. The lower ends of the side bars .of each frame 16 are ivotally connected to a block 17 similar in all respects to the block 9 and formedwith a longitudinal centrally arranged depression 18 in- PatentedNoy. 11, 1913.

teriorly threaded to engage the feed shaft,

The arrangement of the partsfis such that surface of the block 9 with the effect to draw otherand cause the threads in the block depressions to engage the threads of the feed shaft, whereby in the operation of. said shaft the carriage will be moved longitudinally of the casing 1,

Beyond the upper wall of the casing 1 the carriage standard is provided witha head plate 19 designed to support a carrier strip 20, which thus extends transversely of the casing, The strip is preferably of non: conducting material, though if desired it may be made of two ordinary metallic sec- I tions separated-by an insulating strip 21.

Secured inthe top wall of the casing 1 contact bars 22 and 23, each of said bars extending the full length of the casing top and arranged in spaced parallelrelation are inafter termed the recording contact bar,

the casing 1 is provided with a series of longitudinally alined recording contacts 24, these contacts being arranged in spaced relation and in a line parallel with the recording bar contact 22. Beyond the bar contact- 23, and inalinement longitudinally of the casing, are arranged a series of contact points 25 forming the shot contacts, these latter contacts extending in a line parallel to the contact bar 23, hereinafter termed the shot firing contact bar.

The carrier strip 20 is provided with four spaced contact fingers 26,' 27, 28 and 29, these fingers being preferably of curved spring metal and secured to the contactstrip for cooperation with a particular part of the electrical equipment of the mach1ne,,that'1s the 23, the contact finger 28 is designed for suceessive electrical engagement with the con-v tact points 24, while the contact finger 29 is designed for successive coiiperatlon with the a shot firingcontact points 25. Assuming the carrier strip to be of non-conducting material the fingers 27 and 29 are electrically connected by a conductor 30, while the fingers-26 and 28 are similarly connected by a conductor 31 and thereby establish electrical connection between the shot firing contact bar and the shot firing contact points, and also between the recording contact bar and the recording contact points.

Each shot firin contact oint isin connection with a ring con uctor terminal point 32, said points 32 being also secured in the top wall of the casing and respectively alined transverse the casing with the firing contact points. The connection between the respective airs of points 25 and 32 are by means of or inary fuses 33, whereby to prevent passage of an excessive current beyond the points 32. The points 32 are connected by meansof conductors 34 with the respective shots, said conductors 34 preferably leading from the machine in the form of a cable and being divided as necessary-to serve each shotwith a single conductor, the returns from all shots being grounded. This particular feature is not important in the present invention and no further detailed description thereof is deemed necessary herein.

Each machine is provided with a motor 35, on the armature shaft of which is arranged a worm to at all times engage and operate the worm gear 5 on the feed shaft. The machines are adapted to be used in series throughout the mines, and for this reason I provide means whereby when each machine has completed its shot firing operation it will automatically disconnect itself from the power service and connect the next succeeding machine to said service. To this end each machine is p'rovided with a switch blade 36 pivotally mounted at an appropriate point in the machine and designed to play between two pairs of spaced contacts, the first pair 37 and 38 of which are the service contacts of the particular machine in which the switch is mounted, while the second pair 39 and 40 are the service contacts of the next succeeding machine. The switch blade, which is of insulating material carriescontacts 4142 adapted for engagement with the contacts of each respective pair in accordance with the position of the blade, and the said contacts 41 and 42 are, in the initial or first machine of the series, connected with the service conductors 43-44. From the machine contacts 3738 conductors 4546 lead to the respective contact bars 2223, the motor being included in the circuit. Theswitch blade is held under the tension of a spring 47 so that its normal tendency is to coiiperate with the contacts 39 and 40, but I mounted adjacent t e free end of the switch so that when said lever is engaged with the switch the latter is held so as to direct the power of service conductors 43 and 44 through the machine conductors 45-46.

provide a trip lever 48 The carrier strip 20 is provided with a trip arm 49, which, when said carrier strip will engage the trip lever 48 and release the switch 36 to the influence of the spring 47 whereby said switch will immediately cut out the machine in which it is mounted and cut in the next succeeding machine, it being understood that the contacts 39 and 40 are by conductors5051 connected to the next succeeding machine.

I will now proceed to describe the recording device, it being understood, however, that such specifically forms the subject matter of a copending application filed May 4, 1909, Serial No. 493,791, and is described herein simply to render clear the effective operation of the firing machine forming the subject matter of this invention.

The recording apparatus comprises a machine mounted at the surface of the mine including a disk 52 bearing a series of lines dividing the same into squares each correspending with one shot, the squares being preferablyarranged in concentric series so that each machine corresponds to one series of squares. The machine is mounted for rotation being provided with a ratchet 53 designed to be operated by a lever 54 carrying a pawl 55 and spring pressed through the medium of a spring 56 in one direction, the opposite end of the lever having an armature strip 57 designed to be controlled by an electro-magnet 58, the parts being arranged so that upon energization of the .electro-magnet the lever 54 will be operated operated provide spaced punches oropenings in the particular square underlying the implements. Each of the perforating 1mplements are in the form of levers pivotally mounted in an appropriate manner and operated by electro-magnets 61 and 62 respectively. j The service conductors 43 and 44 lead from any suitable source of current supply at the surface of the mine, the former leading direct to the contact 37 of the first machine while the latter leads, through ordinary clectro-magnets 63 and 64, the service conductor forming the windings of the electro-magnets. These respective magnets are wound for difierent current strengths, that is the armature of the electro-magnet 63 will be attracted when a current of a certain strength is passing through the service conductor, while the armature 66 of the electro-magnet 64 will only be attracted by a current of greater strength. Hence it is possible for a current of predetermined strength to pass through the service conductors and only energize one of the electro-magnets, as 63, while if the greater current passes through the wire of course both of the. electro-magnets 63 and .64 will be operated. The armatures 65 and 66 form in effect switches or closures for secondary circuits, that controlled 1 by the armature 65 including conductors 67 which energize the electro-magnet 61 of the perforating implement 59 while the armature 66 is included in a circuit comprising conductors 68 which control the electro-magnet 62 of the perforating implement 60, both the secondary circuits terminally including the service conductors 43 and 44, and if desired suitable resistance as incandescent lights 69. The electro-magnet 58 for feeding, the disk 52 is ener 'zed by conductors 70 and 71, the former 0 which is connected to the service conductor 43, while the latter leads to the firing machine and isconnected to each of the recording vcontacts24 by conductors 72.

In the normal operation of the machine the closing of the service circuit at the surface of the mine after the shots have beenproperly fired will, through the motor, cause a rotation of the feed shaft 3, and hence the travel of the carriage longitudinally of the casing. As the carriage travels throughout the length of the casing itwill successively engage the shot contacts and record contacts, firing the shots in succession and also energizing the electro-magnet 58 to advance the record disk 52 ste by step, it being noted, however, that t e actual movement of the disk being under the influence of the spring 56 occurs only while the contact fin-.

ger 28 is passing between the respective contacts, or when no current is flowin through the machine other than through t 0 motor. If the machine is in normal operation 'the current strength will operate electroing implements.

ticular shot. If a short circuit should occur on the service conductor the current will be in suflicient strength to afl'ect the electromagnet 64, alsooperate the electro-mag'net 63, thereby energizing both the electro-magnets 61-62 and operating both the perforat- If for any reason by the breaking of a conductor, or the like no currentis passing, then neither perforating implement will be operated, so that the disk will indicate at each shot whether or not the shot was fired, and the reason for the nonfiring in the event such is the result.

The shot firing machine is of simple construction, requiring practically no adjustment on the part of the operator in its initial setting beyond the arrangement of the switch 36 and the positioning of the carria at the forward end of the feed screw, WhlCh latter is readily accomplished by releasing the blocks 9 and 17 b the movement of the lever 12 and moving e carriage longitudinally of the machine by hand.

Having thus described the invention what is claimed as new, is

In a machine of the class described a easing, a series of contacts arranged on the cas-' ing and disposed longitudina y thereof and spaced apart, a contact bar mounted on the casing longitudinally thereof adjacent to said contacts, a second series of contacts ar-. ranged on the casing and disposed longitw dinally thereof and spaced, a second contact bar on the casing arranged longitudinally thereof adjacent to said last contacts, a carriage adapted to travel longitudinally pf said casing and including a carrier strip disposed transversely of the casing, contact fingers arranged on said strip and depending therefrom and spaced apart, connections between said fingers, said connections serving to establish e ectrical' connection between said first-mentioned bar and contacts and said second bar and contacts, to lug on said strip, an electric circuit including said contact bars, a switch controlling said circuit and disposed in the path of movement ofsaid lug whereby the circuit'may be broken when the carriage has reached the end of its path of movement, and means for moving said carriage longitudinally of said casing.

In testimony whereof- I aflix in presence of two witnesses.

GRANT I. RAWSON, Witnesses CLINTON Roon, Bonner H. Kama.

my signature v 

